This submission is one of six from the multicenter Pulmonary AIDS Complications Study (PACS) project. Our primary aim is to continue a study providing data on the frequency and types of lung diseases that occur in persons with HIV infection and to describe the course and outcome of these disorders. Particular attention will be given to identifying patterns of complications among demographic subgroups that have not been extensively studied such as women and blacks, and to defining differences between HIV transmission groups. The unique cohort that has been established by PACS will also provide an opportunity for new insights into particular complications such as airways disease and tuberculosis, allow the testing of novel approaches to the diagnosis of tuberculous infection and the prediction of pulmonary complications, and allow a better definition of the impact of early pulmonary events on the later stages of HIV infection and its complications. This information is essential to the development of clinical strategies and sound policy decisions for the allocation of resources to assist HIV-infected persons. The study will continue to use 6 clinical centers, including University of California, San Francisco, and a data coordinating center. The study will maintain its cohort and its prospective, longitudinal design for the evaluation of participants grouped by HIV infection status and transmission category, and stratified by numbers of circulating CD-4 (T-helper) lymphocytes. Standardized clinical and laboratory studies, of proven value in detecting pulmonary complications, are systematically applied to detect HIV-associated complications. The results of these tests are correlated with demographic and immunologic data. Additional studies using our serum bank will provide us an opportunity to extend preliminary observations relating to the identification of specific complications such as tuberculosis. Data from all components of the study will be transmitted from the Clinical Centers to the Coordinating Center which will monitor performance of the Clinical Centers as well as provide quality control to assure uniformity of data quality. The Coordinating Center will also provide statistical expertise, in addition to that available from within the Clinical Centers, to facilitate the analysis of study data.